Answer:
F = 120 N
Explanation:
Given that,
The mass of a runner, m = 60 kg
Acceleration of the runner, a = 2 m/s²
We need to find the force provided from her legs. The formula for force is given by :
F = ma
Substitute all the values,
F = 60 kg × 2 m/s²
= 120 N
So, the required force is equal to 120 N.
Answer:
α = 0.0135 rad/s²
Explanation:
given,
t = 133 min = 133 x 60 = 7980 s
angular speed varies from 570 rpm to 1600 rpm
now,
570 rpm =
= 59.69 rad/s
1600 rpm = =
= 167.6 rad/s
using equation of rotational motion
ωf = ωi + αt
167.6 = 59.7 + α x 7980
α x 7980 = 107.9
α = 0.0135 rad/s²
Answer:
5541Hz
Explanation:
If the frequency of a wave is directly proportional to the velocity we have;
F = kV where;
F is the frequency
K is the constant of proportionality
V is the velocity
Since f = kV
K = f/v
K = F1/V1 = F2/V2
Given f1 = 412Hz v1 = 25.8m/s f2 = ? V2 = 347m/s
Substituting in the formula we have;
412/25.8=f2/347
Cross multiplying
25.8f2 = 412×347
F2 = 412×347/25.8
F2 = 5541Hz
The frequency heard will be 5541Hz
Answer:
Momentum is always conserved, and kinetic energy may be conserved.
Explanation:
For an object moving on a horizontal, frictionless surface which makes a glancing collision with another object initially at rest on the surface, the type of collision experienced by this objects can either be elastic or an inelastic collision depending on whether the object sticks together after collision or separates and move with a common velocity after collision.
If the body separates and move with a common velocity after collision, the collision is elastic but if they sticks together after collision, the collision is inelastic.
Either ways the momentum of the bodies are always conserved since they will always move with a common velocity after collision but their kinetic energy may or may not be conserved after collision, it all depends whether they separates or stick together after collision and since we are not told in question whether or not they separate, we can conclude that their kinetic energy "may" be conserved.
Answer:
she need to use 20 cm thick
Explanation:
given data
wants the attic insulated = R-30
purchased = 10 cm thick
solution
as per given we can say that
10 cm is for the R 15
but she want for R 30
so
R 30 thickness =
R 30 thickness = 20 cm
so she need to use 20 cm thick