Answer:
356 N
Explanation:
Newton's second law of motion describes the relationship between an object's mass and the amount of force needed to accelerate it.
here there is a weight acting downwards on the object , yet it is accelerating upwards shows that there is a net force upwards
Applying Newtons second law of motion upwards ,
Force = mass *acceleration
Upward force - m*g = m *a
F_up= 20 *8 + 20 * 9.8
= 356 N
Upward force= 160 N
Answer:
Explanation:
Average velocity is defined as the ratio of total displacement of the motion and total time taken in that motion
here we know that initially the sky diver drops without opening parachute by total displacement 625 m
then she open her parachute and drop another 362 m
so first it took time t = 15 s to drop without open parachute
then it took t = 139 s to drop next displacement
so here total displacement is given as
total time is given as
so average velocity is given as
Answer:
d = 10.2 m
Explanation:
When the car travels up the inclined plane, its kinetic energy will be used to do the work in climbing up. So according to the law of conservation of energy, we can write that:
where,
m = mass of car
v = speed of car at the start of plane = (36 km/h)(1000 m/1 km)(1 h/3600 s)
v = 10 m/s
F = force on the car in direction of inclination = W Sin θ
W = weight of car = mg
θ = Angle of inclinition = 30°
d = distance covered up the ramp = ?
Therefore,
<u>d = 10.2 m</u>