Select the correct answer.
2 answers:
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Answer:
Shortest time = 3.47 seconds
Explanation:
We know that Force of gravity of an object is given by;
F_g = mg
Also, Force due to kinetic friction is given as;
F_friction = μ_k•F_n
Force due to static friction is given as;
F_static = μ_s•F_n
Where ;
μ_k = coefficient of kinetic friction
μ_s = coefficient of static friction
F_n = Normal Force
Let's solve for the static crate.
From the free body diagram i attached, the resultant force in the vertical y direction will be;
N - mg = 0
Thus, N = mg
WherN is the
From earlier, we know that;
F_static = μ_s•F_n
Thus,
F_static = μ_s•mg
Now, in the horizontal x direction,
F_static = ma
Thus,
μ_s•mg = ma
m will cancel out, and;
a = μ_s•g
a = 0.3 x 9.81 = 2.943 m/s²
Not, to get the final the final speed of the tool box, we'll use;
V_f = V_i + a•Δt
Where;
Δt is shortest time.
V_f = final velocity
V_i = initial velocity
Thus, making Δt the subject, we have;
Δt = (V_f - V_i)/a = (10.2 - 0)/2.943 = 3.47 s
Answer:a)45cos40 b)45sin40 c) 2.95 d)102
Explanation:
a)
b)
c) Since air resistance is negligible, the only force acting on the golf ball is gravity. Thus, its vertical acceleration is -<em>g</em>. We know the final velocity must be 0 m/s, because this will be when the golf ball reaches the maximum height and starts to change direction (it falls back to the ground). We also know initial velocity in the vertical direction (see part b). Thus, we can use this equation: .
d) The horizontal distance traveled is dependent on (1) how long the ball is in the air and (2) what the horizontal velocity is. (1) was found in part c, and (2) was found in part a.
(a) Force between the two charges
The electrostatic force between the two charges is given by:
where k is the Coulomb's constant, q1 and q2 the two charges, r their separation.
In this problem:
Substituting into the equation, we find
(b) direction of particle q2
Particle q2 wants to move in the direction of the force acting on it. The direction of the force depends on the relative sign of the two charges: like charges attract each other, opposite charges repel each other. In this case, the two charges are both positive, so they repel each other and q2 tends to move away from particle q1.