Answer:
same problem is here also bro i cannot find this plz help anyone
Answer:252 miles
Explanation:
Given
During his way to mountain it took 7 hr to drive
and during his return trip it took 4 hr to return
Let x be the distance between home and mountain
average speed for return is 27 miles per hour faster than his former trip
let v be the speed on his way to mountain thus v+27 is his return speed
thus
----1
for return trip
-----2
divide 1 & 2




thus 
Answer:
The liquid turns to a gas.
Explanation:
If a liquid is heated the particles are given more energy and move faster and faster expanding the liquid. Particles in the middle of the liquid form bubbles of gas in the liquid.
Answer:
10000 J or 10 KJ
Explanation:
power = workdone/time taken
400 = workdone/25
workdone = 400 * 25
=10000 J
Answer:
(d) a net external force must be acting on the system
Explanation:
Momentum is given as the product of mass and velocity.
P = MV
According to Newton's second law of motion, " Force applied to a body (system) is directly proportional to the rate of change of momentum of the body (system) which takes place in the direction of the applied force (external force).
F ∝ΔMV
Therefore, If the total momentum of a system is changing, a net external force must be acting on the system.
(d) a net external force must be acting on the system