Answer:
Friction always acts in the direction opposing motion. This means if friction is present, it counteracts and cancels some of the force causing the motion (if the object is being accelerated).
Explanation:
Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other.
Answer:

Explanation:
As we know that volume is given as

so it is given in liter as

now we have six pack of such volume
so total volume is given as


so its mass is given as

now the change in temperature is given as


now the heat given to the liquid is given as




Answer: It will amount to 11p after 20 years.
Explanation:
Formula :
Simple interest = Principal x rate x Time (i)
Amount = Principal + Interest
Amount = Principal + Principal x rate x Time
Amount = Principal (1+ rate x Time) (ii)
Given: Principal = p
After 1 year , amount = 1.5p
After 3 years , amount = 2.5p
From (ii)

Amount after 20 years = p(1+ 0.5 x 20) = p(1+10)=11p
It will amount to 11p after 20 years.
Answer:
v = 22.54 mph.
Explanation:
Given that,
Distance moved, d = 200 m
Time, t = 19.8 s
We need to find the runner's average speed.
We know that,
1 mile = 1609.34 m
200 m = 0.124 miles
19.8 seconds = 0.0055 h
So,
Speed = distance/time

So, the runner's average speed is 22.54 mph.