Answer:
13.309 m/s²
Explanation:
Length from shoulder to hand, l = 30 cm = 0.3 m
initial velocity, u = 1 m/s
final velocity, v = 2.5 m/s
time, t = 3 s
Let the tangential acceleration is a.
by using first equation of motion
v = u + at
2.5 = 1 + 3 a
a = 0.5 m/s²
Let the centripetal acceleration is a'.
a' = v'²/l
a' = 2 x 2 / 0.3
a' = 13.3 m/s²
The tangential acceleration and the centripetal acceleration are both perpendicular to each other. So, the net acceleration is given by
A = 13.309 m/s²
F=ma
m=F/a=95/0.8= 118.75kg
your friend is pretty heavy XD
Its tangential speed is constant although its velocity is changing. As the object changes direction, it results in a changing of positive and negative signs of the velocity. Although, the magnitude of the velocity (speed) is not changing.
Explanation:
average speed = total distance travelled / total time travelled
time to travel the first 6km: 6 / 50 = 3/25 (h)
time to travel the next 6km: 6 / 90 = 1/15 (h)
[I think there's problem in the question 'cause 900km/h sounds impossible for normal person to travel in normal condition]
The total time: 3/25 + 1/15 = 14/75 (h)
Average speed over the 12 km drive will be:
