Explore BrainMass
Share

# Acceleration

### Rocket driven car - Expression for acceleration

Please see attachment for full problem description. A rocket-driven car of total mass M loses mass at a constant rate lembda per unit of time at a constant ejection speed V relative to the car. If the total resistance to motion is kv with the speed is v, show that the acceleration of the car along a straight horizontal road i

### Parametric Equations : Describing the Motion of a Ball

A baseball pitcher throws a baseball with an initial velocity of 133 feet per second at an angle of 20° to the hoizontal. The ball leaves the pitcher's hand at a height of 5 feet. Find parametric equations that describe the motion of the ball as a function of time. How long is the ball in the air? When is the ball at its maximu

### Set of 15 problems on gravitation.

1. Given the perihelion distance, aphelion distance and speed at perihelion of a planet, which of the following cannot be calculated? a) the mass of the start b) the mass of the planet c) the speed of the planet at aphelion d) the period of orbit e)the semimajor axis of the orbit 2. The mass density of a certain planet

### force applied to the block and slab system

Please see attached file for full problem description. A 4.40-kg block is placed on top of a 5.50-kg slab. If the slab is held fixed, the block can be made to slip only if a minimum force of 12.0 N is applied to it. The assembly is now placed on a horizontal, frictionless surface, as shown in the diagram. a) What is th

### average speed and acceleration

1) If you travel 1 mile AT THE SPEED OF 1000 mi/h, and another mile at the speed of 1 mi/h, what is your average speed? 2) A body with an initial velocity of 8m/s moves with constant acceleration and travels 640m in 40sec. What is its acceleration?

### Physics: velocity and acceleration

1) An icecream truck is moving at 20m/s. It then speeds up for 5 seconds at 8m/s. what is its velocity at this time? 2) A rocket in space moves at constant velocity of 9.8m/s then it uses propulsion system to accelerate to 10m/s guring 3min. burndown. What is accelearation of the rocket?

### Two blocks of masses m1=20kg and m2=10kg are being pushed against each other on a flat frictionless tables with a horizontal force of P=600N, as shown below.

Please see the file attached. Its one problem #5. Please help me in solving the problem stepwise. Two blocks of masses m1=20kg and m2=10kg are being pushed against each other on a flat frictionless tables with a horizontal force of P=600N, as shown below.

### Newtons Law's of Motion. Painter on Platform Pulling Himself

4. A painter of mass 70.0 kg stands on a platform of mass 75.0 kg and pulls on two ropes which hang over pulleys. He pulls each rope with a force of 750.0 N. Assuming a coordinate system where +y is up, calculate the y-component of the acceleration ay. ay can either be positive or negative depending on the direction of the accel

### Magnitude of force and acceleration

A 4.44 kg block located on a horizontal frictionless floor is pulled by a cord that exerts a force F=10.7N at an angle theta=22.0degrees above the horizontal, as shown. What is the magnitude of the acceleration of the block when the force is applied? What is the magnitude of the normal force acting on the block when the force

### Average Net Force/Acceleration

1. During a circus performance, a 73.0-kg human cannonball is shot out of an 17.7-m-long cannon. If the human cannonball spends 0.812 s in the cannon, determine the average net force exerted on him in the barrel of the cannon. (Assume an the acceleration is constant.) 2. A newly discovered planet has a mass that is 1.45 times

### Relativistic Energy and Momentum

1. Given: The charge on the electron is qe = 1.60218 *10 ^-19 C. Given: The mass of the electron is me = 9.10939 * 10 ^-31 kg. What is an electron's momentum, if it is accelerated across a 6 mm potential difference of 220 kV? Answer in units of keV/c. 2. Determine the energy required to accelerate an electron

### Electric Force and Coulomb's Law between Two Point Charges

Objects A and B are both positively charged. Both have a mass of 500 g, but A has twice the charge of B. When A and B are placed 50.0 cm apart, B experiences an electric force of 0.810 N. 1) How large is the force on A? 2) What are the charges q_A and q_B? 3) If the objects are released, what is the initial acceleration of

### Acceleration and Force/Newton's Laws of Motion

Acceleration & Force : 1. Calculate the average acceleration of a car that changes speed from 0 m/s to 15 m/s in 5 s. 2. Suggest why placing wheels under a heavy box reduces the necessary force required to push it along at a constant speed. 3. Evaluate the change of motion in the following cases in which the forces o

### Physics Questions on Impact, Speed, Acceleration

1. In her Mustang, Kelly rounds a curve onto a straight section of country road while traveling at 45 mph, only to find a fully loaded manure spreader completely blocking the road 37 m ahead of her. Startled, she travels at a constant velocity for 0.80 s of reaction time, then hits the brakes and slows with a constant accelerati

### Change in momentum and average force

A 1 kg softball is pitched to you at 10 m/s. You hit the ball back along the same path, and at the same speed. A). If the bat was in contact with the ball for .01 seconds, find the magnitude and direction of an average force the bat exerted. B). Find the magnitude of the impulse acting on the ball. C. Find the change in

### Stress, Strain, and Hooke's Law

An 1560 kg car, being lifted at a steady speed by a crane, hangs at the end of a cable whose radius is 3.5 10-3 m. The cable is 14 m in length and stretches by 10.5 10-3 m because of the weight of the car. Determine each of the following for the cable. (a) the stress (b) the strain (c) Young's modulus

### Linear speed of a bicycle chain and centripetal acceleration

The front and rear sprockets on a bicycle have radii of 9.00 and 5.10 cm, respectively. The angular speed of the front sprocket is 8.00 rad/s. (a) Determine the linear speed (in cm/s) of the chain as it moves between the sprockets and (b) Determine the centripetal acceleration (in cm/s2) of the chain as it passes around t

### apparent weight of the person in an elevator

A 75.0 kg person stands on a scale in an elevator. What is the apparent weight in each of the following situations? (a) when the elevator is accelerating upward with an acceleration of 1.80 m/s2 (b) when the elevator is moving upward at a constant speed (c) when the elevator is accelerating downward with an acceleratio

### Elementary Differential Equations

64. (The clepsydra, or water clock) A 12 hour water clock is to be designed with the dimensions shaped like the surface obtained by revolving the curve y = f(x) around the y-axis. What should be this curve, and what should be the radius of the circular bottom hole, in order that the water level will fall at the constant rate o

### Determine if the disk slips at this instant.

Problem # 9 - The semicircular disk having a mass of 10 kg is rotating at &#61559; = 4 rad/s at the instant &#61553; = 60&#61551; . If the coefficient of static friction at A is &#61549; s = 0.5, determine if the disk slips at this instant. See attached file for full problem description.

### Minimum acceleration for the fireman

A fireman wants to slide down a rope. The breaking load for the rope is 3/4th of the weight of the man. With what minimum acceleration should the fireman slide down?

### Force of Friction over a Pulley

1. Two masses are attached with a pulley over an incline which is over a platform. The top of the incline to the ground is 6m. There is one mass on that ramp which is 5.0kg. The other mass which is hanging freely off the ramp is 20.0kg. The force of kinetic friction between the 5.0kg mass and the ramp is .26. The 5.0kg mass is a

### Bounce for a moving car

The car with its passengers is traveling along a horizontal road when it suddenly runs onto a new piece of road surface, raised 5.5 cm above the old surface. Assume that this suddenly raises the wheels and the bottom ends of the springs through 5.5 cm before the body of the car begins to move upward. In the ensuing rebound, are

### Work done by a force at angle

An object of mass = 2 kg is pulled by a constant force F = 4 N for a horizontal distance of 2 m. (the rope pulling the mass is at an angle of 30 degrees above the horizontal) What is the work done along the positive x axis? Neglect friction. 8 kg m/s^2 8 kg m^2/s^2 7 kg m/s^2 7 kg m^2/s^2

### Plane Reversing Course

1. In airplane traveling at 529 km/hr needs to reverse its course. The pilot decides to accomplish this by banking the wings at an angle of 41.0 degrees. a) Find the time needed to reverse course. b) How heavy would a 56 kg passenger feel during the turn? In other words, what would be the magnitude of the total force exerte

### How long does it take car A to overtake car B given different accelerations?

Car A is traveling at 18.0 m/s and car B at 25.0 m/s. Car A is 300 m behind car B when the driver of car A accelerates his car with an acceleration of 1.80 m/. How long does it take car A to overtake car B? 5.50 s 12.6 s 22.6 s Car A never overtakes car B.

### Projectile motion with angles

A football is kicked at an angle of 50 degrees and travels a distance of 20 m before hitting the ground. a. What is the initial speed of the ball? b. How long is it in flight? c. How high does it rise?

### Force Exerted by rope on crate

A 40.0-kg crate is being lowered by means of a rope. Its downward acceleration is 2.00 m/. What is the force exerted by the rope on the crate? 40.0 N 232 N 312 N 472 N A 40.0-kg crate is being raised by means of a rope. Its upward acceleration is 2.00 m/. What is the force exerted by the rope o

### Force exerted by the rope on the crate

A 40.0-kg crate is being lowered by means of a rope. Its downward acceleration is 2.00 m/. What is the force exerted by the rope on the crate? 40.0 N 232 N 312 N 472 N A 40.0-kg crate is being raised by means of a rope. Its upward acceleration is 2.00 m/. What is the force exerted by the rope on th