Answer:
As you said you already know, energy cannot be created or destroyed.
Explanation:
You cannot gain energy or lose energy, it can only be converted. So if you start on a 3m high hill and go down it, your potential energy is equal to mgh, and if you get to the bottom of the hill, your KE would be equal to your PE at the top, and when you start going up another hill again, the maximum height you can reach is 3m, because energy cannot be created or destroyed, and your mass and gravitational acceleration are the same, so therefore you can only reach the same height you started from due to the conservation of energy.
Answer:
c. Momentum is the product of mass and velocity
e. Momentum is a vector quantity
g. Momentum has unit of kgm/s
Explanation:
Linear momentum P
P = m .v
m =mass
v=Velocity
If mass take in kg and velocity is in m/s then momentum p will be in kg.m/s.
1. momentum is the product of velocity and mass.
2.Momentum is a vector quantity.
3.Momentum have kg.m/s unit.
So the following option are correct.
c. Momentum is the product of mass and velocity
e. Momentum is a vector quantity
g. Momentum has unit of kgm/s.
Note-
1.Joule is the unit of energy.
2.One-half the product of mass and the square of the object's speed is known as kinetic energy.
Answer:
The horizontal distance travelled in that time lapse is 12.94 m
Explanation:
In order to solve this problem, we'll need:
- The horizontal speed
- the time the hammer takes to fall from the roof to the ground
At the lowest point of the roof, the hammer has a 9.88 m/s speed that makes an angle of 27° with the horizontal, so we can calculate the horizontal and vertical speed with trigonometry. If we take right as x positive and down as y positive we get

Now, we make two movement equation as we have a URM (no acceleration) in x and an ARM (gravity as acceleration) in y. We will wisely pick the lowest point of the roof as the origin of coordinates


Now we calculate the time the hammer takes to get to the floor
or 
Now, we keep the positive time result and calculate the horizontal distance travelled

Answer:
Explanation:
Let after time t , Tina catches up David .
Distance travelled by them are equal ,
Distance travelled by Tina
s = ut + 1/2 a t²
= .5 x 2.10 t²
= 1.05 t²
Distance travelled by David
= 30 t ( because of uniform velocity )
1.05 t² = 30t
t = 28.57 s
Distance travelled by Tina
= 1/2 a t²
= .5 x 2.10 x 28.57²
= 857 m approx.
Momentum = Mass × Velocity
According to this formula,
Momentum of deer = 176 × 19 = 3344 kg•m/s.
Since you are heading north and the deer is running towards you, the direction of the deer' s momentum is north as well.