Answer:0.69
Explanation:
Coefficient of kinetic friction=f/R=61.8/90=0.69
Answer:
A. The waves in the water travel faster and at a higher frequency than they travel on land.
Explanation:
The main reason why human ears can hear dolphins' vocalizations while under the water but cannot hear them well on land is because water is denser than air and air particles travel faster in denser particles.
Denser particles also ensures that the frequency of the waves move faster which in turn produces a faster and louder result.
Volume = mass / density = 45.6/10.5 = .... L
D. Riding a bike uphill
Increased height = increased potential energy
Answer: 75.05N
Explanation:
According to newton's second law,
Force = mass×acceleration
Given mass = 5.0kg
Acceleration = change in velocity/time
Velocity = change in displacement/position/time i.e dy/dt
Given position of the particle as y(t)=(2.80 m/s)t +(0.61 m/s)t³
dy/dt = 2.80 + 3(0.61)t²
V = dy/dt = 2.80 + 1.83t²
Acceleration (a) = dv/dt = 2(1.83)t
dv/dt = 3.66t
To get the force when t =4.10second
dv/dt @ t = 4.10s will be 3.66(4.10)
acceleration = 3.66×4.10 = 15.01m/s²
Magnitude of the force F = ma
F = 5.0kg × 15.01m/s²
F = 75.05N
