The RATE of producing, moving, converting, or using energy is "power".
The unit is "watt". 1 watt means 1 joule of energy per second.
Answer:
Speed is a scalar quantity it has only magnitude. So in the given scenario the student actually described about the velocity.
Explanation:
In this situation, student is describing that the speed is -10 m/s. The speed with the negative sign is wrong because speed is a scalar quantity and scalar quantities have only magnitude, they do not have direction. So, his statement is wrong because he is describing the speed with the negative sign.
And also we know that velocity is a vector quantity, so it has magnitude as well as direction also. So in this situation, the student is actually want to describe the velocity because he is mentioning the magnitude in a particular direction.
Answer:
0.705 m/s²
Explanation:
a) The sprinter accelerates uniformly from rest and reaches a top speed of 35 km/h at the 67-m mark.
Using newton's law of motion:
v² = u² + 2as
v = final velocity = 35 km/h = 9.72 m/s, u = initial velocity = 0 km/h, s = distance = 67 m
9.72² = 0² + 2a(67)
134a = 94.484
a = 0.705 m/s²
b) The sprinter maintains this speed of 35 km/h for the next 88 meters. Therefore:
v = 35 km/h = 9.72 m/s, u = 35 km/h = 9.72 m/s, s = 88 m
v² = u² + 2as
9.72² = 9.72² + 2a(88)
176a = 9.72² - 9.72²
a = 0
c) During the last distance, the speed slows down from 35 km/h to 32 km/h.
u = 35 km/h = 9.72 m/s, v = 32 km/h = 8.89 m/s, s = 200 - (67 + 88) = 45 m
v² = u² + 2as
8.89² = 9.72² + 2a(45)
90a = 8.89² - 9.72²
90a = -15.4463
a = -0.1716 m/s²
The maximum acceleration is 0.705 m/s² which is from 0 to 67 m mark.
The best way to think of 'per' is as the equivalent of 'for each'.
