Share
Explore BrainMass

# Modern Physics - 5 Questions

1) A 56 g ball is dropped from a height of 1.20 m above the top of a spring with a spring
constant of 260 N/m. How far is the spring compressed at it maximum compression

2) When a spring is stretched to twice the distance, the potential energy of the spring is
B) doubled
C) quartered
D) halved

3) To accelerate your car at a constant acceleration, the car's engine must
A) maintain a constant turning speed
B) develop ever-increasing power
C) maintain a constant power output
D) develop ever-decreasing power

4) How much work is when a constant horizontal 20-N force pushes a 50-kg a distance
of 10 m on a horizontal surface?
A) 50 J
B) 100 J
C) 200 J
D) 400 J

5) A 3.00 kg toy falls from a height of 10.0 m. Just before hitting the ground, what will
be its kinetic energy? (Disregard air resistance)
A) 98.0 J
B) 0.98 J
C) 294 J
D) 29.4 J

#### Solution Preview

(1) PE of the mass = mgh = 0.056 * 9.8 * 1.2 = 0.6586 J

This energy is converted into work and this work compresses the spring

W = (1/2) k x^2

0.6586 = (1/2) * 260 * x^2

Solving, we get ...

#### Solution Summary

Complete, Neat and Step-by-step Solutions are provided.

\$2.19