At which point should a researcher inform the respondents about the use of deception in a psychological study ??

Running at 2 m/s, Bruce the 45 kg quarterback, collides with Biff, the 90 kg tackle, who is traveling at 7 m/s in the other dire

melomori [17]

Given data

*The mass of Bruce is m_1 = 45 kg

*The initial velocity of the Bruce is u_1 = 2 m/s

*The mass of the biff is m_2 = 90 kg

*The initial velocity of the Biff is u_2 = -7 m/s

*The final velocity of the first glider is v_2 = -1 m/s

According to the law of conservation of linear momentum, the total linear momentum of a system remains constant

Applying the law of conservation of momentum as

$\begin{gathered} p_i=p_f \\ m_1u_1+m_2u_2=m_1v_1+m_2v_2 \\ v_1=\frac{m_1u_1+m_2u_2-m_2v_2_{}_{}_{}_{}}{m_1} \end{gathered}$

Substitute the known values in the above expression as

$\begin{gathered} v_1=\frac{(45)(2)+(90)(-7)-(90)(-1)}{45} \\ =-10\text{ m/s} \end{gathered}$

Hence, the speed of the bruce knock backwards is v_1 = -10 m/s

3 0

2 years ago

If y(t)y(t) describes the position with time, what is the proper formula for velocity with time? (Recall velocity is related to

PilotLPTM [1.2K]

Answer:

Although this question is not complete, I would give a general solution to this kind of problems.

If y(t) describes the position of a body with time such that

y(t) = at^(n) + bt^(m) + C

Then

V(t) = dy(t)/dt = ant^(n-1) + bmt^(m-1)

Explanation:

As an example supplies the position of a particle is given by

y(t) = 4t³- 3t² + 9

V(t) = 4x3t²- 3x2t¹

V(t) = d(t)/dt = 12t² - 6t.

Another example,

If y(t) = 15t³ - 2t² + 30t -80

V(t) = d(t)/dt = 15x3t² - 4t +30 = 45t² + 4t + 30.

Basically, in the equations above the powers of t reduces by one when computing the velocity function from y(t) by differentiation (calculating the derivative of y(t)). The constant term C (9 and 80 in the functions of y(t) in examples 1and 2 above) reduces to zero because the derivative of a constant (and ordinary number without the t attached to it) is always zero.

One last example,

y(t) = 2t^6 -3t²

V(t) = d(t)/dt = 12t^5 - 6t

6 0

4 years ago

Josh starts throwing his pitch; we assume that his arm moves in a perfect circular arc, and his arm is 0.7 m long. If he needs t

harina [27]

As we know that centripetal acceleration is given as

$a_c = \frac{v^2}{R}$