True or false: Alcohol can cause an uncontrolled ________ of the eyes, making good vision almost impossible

. A rope is being used to pull a mass of 10 kg vertically upward. Determine the tension on the rope, if starting from rest, the

telo118 [61]

$\text{Given that,}\\\\\text{Mass, m =10 kg}\\\\\text{Time, t = 8 sec}\\\\\text{Velocity, v = 4~m/s}\\\\\text{When a body is moving upwards,}\\\\\text{Tension,}~ T=mg +ma\\\\~~~~~~~~~~~~~~~=mg+m\left(\dfrac{v-u}t \right)\\\\~~~~~~~~~~~~~~~=10(10)+10\left(\dfrac{4-0}8\right)\\\\~~~~~~~~~~~~~~~=100+10\left(\dfrac 12\right)\\\\~~~~~~~~~~~~~~~=100+5\\\\~~~~~~~~~~~~~~~=105~N$

5 0

2 years ago

so I know you can solve this either by using Vox or Voy. I'm getting 3.08s when using Vox and 3.14s for Voy way. For Voy I'm usi

Tatiana [17]

The person's horizontal position is given by

$x=v_0\cos40^\circ t$

and the time it takes for him to travel 56.6 m is

$56.6\,\mathrm m=\left(24.0\,\dfrac{\mathrm m}{\mathrm s}\right)\cos40^\circ t\implies t=3.08\,\mathrm s$

so your first computed time is the correct one.

The question requires a bit of careful reading, and I think there may be a mistake in the problem. The person's vertical velocity $v_y$ at time $t$ is

$v_y=v_{0y}-gt$

which tells us that he would reach the ground at about $t=3.15\,\mathrm s$ . In this time, he would have traveled

$x=v_{0x}(3.15\,\mathrm s)=57.9\,\mathrm m$

But we're told that he is caught by a net at 56.6 m, which would mean that the net cannot have been placed at the same height from which he was launched. However, it's possible that the moment at which he was launched doesn't refer to the moment the cannon went off, but rather the moment at which the person left the muzzle of the cannon a fraction of a second after the cannon was set off. After this time, the person's initial vertical velocity $v_{0y}$ would have been a bit smaller than $\left(24.0\,\frac{\mathrm m}{\mathrm s}\right)\sin40^\circ$ .