Answer:
h = 31.9 m
Explanation:
Since, the ball took 5.1 s in the air. Hence, the time to reach maximum height will be equal to the half of this value:
t = 5.1 s /2 = 2.55 s
Now, we use 1st equation of motion between the time of throwing and the time of reaching maximum height:
Vf = Vi + gt
where,
Vf = Final Velocity = 0 m/s (since, ball momentarily stops at highest point)
Vi = Initial Velocity = ?
g = - 9.8 m/s² (negative sign for upward motion)
Therefore,
0 m/s = Vi + (-9.8 m/s²)(2.55 s)
Vi = 24.99 m/s
Now, we use second equation of motion for height (h):
h = Vi t + (0.5)gt²
h = (24.99 m/s)(2.55 s) + (0.5)(-9.8 m/s²)(2.55 s)²
h = 63.7 m - 31.8 m
<u>h = 31.9 m</u>
Answer:
(M)_A = (M)_b = 76027.5 Nm
Explanation:
Step 1:
- We will first mark each weight from left most to right most.
Point: Weight:
G_3 W_g3 = 6 Mg*g
G_2 W_g2 = 0.5 Mg*g
G_1 W_g1 = 1.5 Mg*g
Load W_L = 2 Mg*g
Step 2:
- Set up a sum of moments about pivot point B, the expression would be as follows:
(M)_b = W_g3 * 7.5 + W_g2*4 - W_g1*9.5 - W_L*12.5
Step 3:
- Plug in the values and solve for (M)_b, as follows:
(M)_b = 9.81*10^3( 6* 7.5 + 0.5*4 - 1.5*9.5 - 2*12.5)
(M)_b = 9.81*10^3 * (7.75)
(M)_b = 76027.5 Nm
Step 4:
- Extend each line of action of force downwards, we can see that value of each force does not change also the moment arms of each individual weight also remains same. Hence. we can say that (M)_A = (M)_b = 76027.5 Nm
Answer:
(c) 16 m/s²
Explanation:
The position is
.
The velocity is the first time-derivative of <em>r(t).</em>
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The acceleration is the first time-derivative of the velocity.

Since <em>a(t)</em> does not have the variable <em>t</em>, it is constant. Hence, at any time,

Its magnitude is 16 m/s².
An object that absorbs all radiation falling on it, at all wavelengths, is called a black body. When a black body is at a uniform temperature, its emission has a characteristic frequency distribution that depends on the temperature. Its emission is called black-body radiation
hope it helps