Answer:
33.6 Ns backward.
Explanation:
Impulse: This can be defined as the product of force and time. The S.I unit of impulse is Ns.
From Newton's second law of motion,
Impulse = change in momentum
I = mΔv................................. Equation 1
Where I = impulse, m = mass of the skater, Δv = change in velocity = final velocity - initial velocity.
Given: m = 28 kg, t = 0.8 s, Δv = -1.2-0 = -1.2 m/s (Note: the initial velocity of the skater = 0 m/s)
Substituting into equation 1
I = 28(-1.2)
I = -33.6 Ns
Thus the impulse = 33.6 Ns backward.
Answer:
a,b,c,e,d
Explanation:
The typical approach by the scientists use to understand the physical world includes the following steps:
Identifying a Problem
Researching the Information
Stating a Hypothesis (Possible Solution)
Testing the Hypothesis
Gather Data
Analysis of the Data
Stating a Conclusion
Publishing the Result
Therefore, according to the question the correct order would be:
a. Observation of physical world.
b. Create hypothesis about observation.
c. Test consequences of hypothesis
e. Adjust results to agree with popular opinion
d. Report outcome
Answer:
a) 
b) 
c) 
d) 
would be the same.
would decrease.
would be the same.
Explanation:
a) On an inclined plane the force of gravity is the sine component of the weight of the block.
b) The friction force is equal to the normal force times coefficient of friction.
c) The work done by the normal force is zero, since there is no motion in the direction of the normal force.
d) The relation between the vertical height and the distance on the ramp is
According to this relation, the work done by the gravity wouldn't change, since the force of gravity includes a term of 
.
The work done by the friction force would decrease, because both the cosine term and the distance on the ramp would decline.
The work done by the normal force would still be zero.
