Answer:
D) 735 J(oules)
Explanation:
Work is defined as force * distance
Force is defined as mass * acceleration
Given a mass of 15 kg and a gravitational acceleration of 9.8 m/s² since the box is being lifted up, the force being applied to the box is 15 kg * 9.8 m/s² = 147 N
Since the distance is 5 meters, the work done is 147 N * 5 m = 735 N/m = 735 J, making D the correct answer.
Answer:
Explanation:
Given
Height of ceiling is 
Initial speed of Putty 
Speed of Putty just before it strike the ceiling is given by
where v=final velocity
u=initial velocity
a=acceleration
s=displacement
time taken by putty to reach the ceiling
Answer:
Explanation:
To stop a ball with high momentum in a small-time imparts a high amount of impact on hands. This is the reason for the stinging of hands.
The momentum of the ball is due to the mass and velocity. To prevent stinging in the hand one needs to lower his hands to increase the time of contact. In this way, the momentum transfer to the hands will be lesser.
The electrons are already there. They are freely moving through the conductor.
Answer:
Explanation:
To solve this problem we use the Hooke's Law:
(1)
F is the Force needed to expand or compress the spring by a distance Δx.
The spring stretches 0.2cm per Newton, in other words:
1N=k*0.2cm ⇒ k=1N/0.2cm=5N/cm
The force applied is due to the weight
We replace in (1):
We solve the equation for m:
