A crane lifts a 400 N crate full of baked beans 15 m. How much work was done by the crane?
1 answer:
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Answer:
10.8s
Explanation:
Given parameters:
Force on the car = 3250N
Distance = 35m
Power = 11375W
Unknown:
Time taken = ?
Solution:
To solve this problem;
Power is the rate at which work is done
Power =
Work done = force x distance = 3250 x 35 = 123200J
Now;
11375 =
11375t = 123200
t = 10.8s
Answer:
C) 3,000 kg m/s
Explanation:
We can consider the horizontal velocity of the motorcycle to be zero, since it rolls off the edge of the cliff very slowly. So, we only need to find the vertical velocity at the time of the impact with the ground.
The vertical velocity of the motorcycle at time t is given by (free-fall motion):
where
is the initial vertical velocity (zero, since the motorcycle is not moving)
g = 9.8 m/s^2 is the acceleration due to gravity
t is the time
Since the motorcycle hits the ground after t = 3 seconds, we have
And since we know its mass, m=100 kg, we can find its momentum:
and the negative sign simply means downward direction.