Answer:
The second snowball hits the ground with a kinetic energy of 100 Joules
Explanation:
Given that,
From the edge of a roof you throw a snowball downward that strikes the ground with 100 J of kinetic energy. It is a case of conservation of energy.
At the highest point,

At lowest point,

From above two equation, we get :
Kinetic energy, K = 100 J
So, the second snowball hits the ground with a kinetic energy of 100 Joules. So, the correct option is (A).
Answer:
The change in power is 4400 W.
Explanation:
Given that,
Power = 10 kW
Speed = 10 m/s
Increases speed = 12 m/s
Given equation is,

We know that,
The power is,

Put the value of F into the formula



We need to calculate the new power
Using formula for power

Put the value into the formula



We need to calculate the change in power
Using formula of change in power

Put the value into the formula




Hence, The change in power is 4400 W.
PART A)
horizontal distance that will be moved = 14 m
Height of the fence = 5.0 m
height from which it is thrown = 1.60 m
angle of projection = 54 degree
So here we can say that stone will travel vertically up by distance

now we will have displacement in horizontal direction

now we know that


now we will have


also for y direction


now from the two equations we will have




now from above equations


So the minimum speed will be 13.2 m/s
Part B)
Total time of the motion after which it will land on the ground will be "t"
so its vertical displacement will be

now we will have




Now the time after which it will reach the fence will be t1 = 1.8 s
so total time after which it will fall on other side of fence


now the displacement on the other side is given as



Answer:
a) 4.485 kg b) 3.94 kg
Explanation:
since the maximum tension the line can stand is 44 N and for question a the speed is constant (acceleration must be zero since the velocity or speed is not changing), F(tension) = mass * acceleration due to gravity (g) .
44 = m * 9.81m/s^2
m = 44/9.81 = 4.485kg
b) F(tension) = ma + mg ( where a is the acceleration of the body and g is the acceleration of the gravity)
44 = m (a +g)
44 = m (1.37 + 9.81)
44/11.18 = m
m = 3.94 kg