B: Gravity.
The force of gravity will pull the car down the hill. The weight/mass of the car also helps this.
A. Base , salt , water,acid
Answer:A
Explanation:
Given
Skier A takes straight, smooth route while Skier B takes curvy, bumpy route to finish.
We know gravity is conservative in nature i.e. work done against it is independent of path followed
So work done by gravity for A and B is same
According to Work energy Theorem Change in the kinetic Energy is equal to work done by all the forces.


where h=vertical height of hill
thus 
which is same for both A and B
Answer:
32 seconds
Explanation:
m1 = 80 kg
m2 = 10 kg
v2 = 5m/s
According to the property of conservation of momentum, assuming that both you and the bag are stationary before the safety rope comes lose:

Since the space station is 20 meters away, the time taken to reach it is given by:

It takes you 32 seconds to reach the station.
Given forceF
1
=5N and F
2
=7N and θ=60
We know resultant force F=
5
2
+7
2
+2(5)(7)cos60
F=
25+49+35
F=
109
it's your answer