Answer:
F n = 0.2 N
Explanation:
given,
you are exerting force of 10 N on the ball.
mass of the ball = 1 kg
acceleration due to gravity = 9.8 m/s²
normal force on the ball = ?
normal force is force exerted by the object to counteract the force from other object.
normal force acting on the ball will be
F n = F - mg
F n = 10 - 1 × 9.8
F n = 10 -9.8
F n = 0.2 N
Hence, normal force acting on the ball is equal to 0.2 N
The speed of sound at T=25°C is Vs=346 m/s. So the sound has to reach the cliff and return back to you so the path it needs to travel is s=2*440 m = 880 m.
Since the speed of sound is constant s=Vs*t, and t= s/Vs=880/346=2.54335 s. You will hear the echo after t=2.54335 s after you shouted.
Answer: The net force acting on the car 1,299.3 N.
Explanation:
Mass of the car = 710 kg
Initial velocity of the car of the ,u= 37 km/h= 10.27 m/s 
Final velocity of the car,v = 120 km/h = 33.33 m/s
time taken b y car = 12.6 sec
v-u=at





The net force acting on the car 1,299.3 N.
Answer:
18m/s^2
Explanation:
Vf = Vi + at
t = distance/ average velocity
(120 + 0)/2 = 60 (average velocity)
400m/60m/s = 20/3 s
insert into first equation:
120 = 0 + a(20/3)
360 = 20a
18 = a
HOPE THIS HELPS!!!