Answer:
The runner's acceleration as she sped up to the finish line is 0.95m/s²
Explanation:
Acceleration is the change in velocity of a body with respect to time. It is expressed as;
Acceleration = change in velocity/time
Change in velocity = final velocity - initial velocity
Acceleration = final velocity - initial velocity / time
Given initial speed = 8.0m/s
Final speed = 9.9m/s
Time taken = 2.0s
Acceleration = 9.9-8.0 / 2.0
Acceleration = 1.9/2
Acceleration = 0.95m/s²
Answer:
Sink
Explanation:
Water has a density of 1 g/cm³. Since the density of the rock is greater than the density of water, the rock will sink.
Answer:
The two moments must be the same:
p1=p2
m1v1=m2v2
v2=(m1v1)/m2
v2=(90 kg x 0.9 m/s)/110kg=0.7 m/s
Answer:
a) 37.8 W
b) 2 Nm
Explanation:
180 g = 0.18 kg
We can also convert 180 revolution per minute to standard angular velocity unit knowing that each revolution is 2π and 1 minute equals to 60 seconds
180 rpm = 180*2π/60 = 18.85 rad/s
We can use the heat specific equation to find the rate of heat exchange of the steel drill and block:

Since the entire mechanical work is used up in producing heat, we can conclude that the rate of work is also 37.8 J/s, or 37.8 W
The torque T required to drill can be calculated using the work equation


