Matter is anything that has

A particle beam is made up of many protons, each with a kinetic energy of 3.25times 10-15 J. A proton has a mass of 1.673 times

ArbitrLikvidat [17]

Answer:

The magnitude of a uniform electric field that will stop these protons in a distance of 2 m is 1.01 x $10^{-4}$ N/C

Explanation:

given information,

kinetic energy, KE = 3.25 x $10^{-15}$ J

proton's mass, m = 1.673 x $10^{-27}$ kg

charge, q = 1.602 x $10^{-19}$ C

distance, d = 2 m

to find the electric field that will stop the proton, we can use the following equation:

E = F/q

= (KE/d) / q , KE = Fd --> F = KE/d

= KE/qd

= (3.25 x $10^{-15}$ J) / (1.602 x $10^{-19}$ C)(2 m)

= 1.01 x $10^{-4}$ N/C

3 0

3 years ago

Energy of a SpacecraftVery far from earth(at R=\infty), a spacecraft has run out of fuel and its kineticenergy is zero. If only

Firdavs [7]

Answer:

$s_e=\sqrt{\frac{2GM_e}{R_e^2}}$

Explanation:

In this case mechanical energy is conserved, which means that the sum of the initial kinetic energy and initial potential gravitational energy will be equal to the sum of the final kinetic energy and final potential gravitational energy:

$K_i+U_i=K_f+U_f$

Which in our case will be:

$\frac{mv_i^2}{2}+\frac{-GM_em}{r_i^2}=\frac{mv_f^2}{2}+\frac{-GM_em}{r_f^2}$

Which, since $v_i=0m/s$ , $r_i=infinity$ , $r_f=R_e$ , $v_f=s_e$ and canceling <em>m</em> means that:

$\frac{s_f^2}{2}=\frac{GM_e}{R_e^2}$

Solving for the final velocity we get:

$s_e=\sqrt{\frac{2GM_e}{R_e^2}}$

6 0

3 years ago

An astronaut floating at rest in space throws a wrench in one direction and subsequently recoils back with a velocity in the opp

Jobisdone [24]

Answer:

a) ll and Ill only

Explanation:

Let the mass of the wrench = m

and the mass of the astronaut = M

Initially, the velocity of the astronaut and wrench are zero.

The astronaut throws the wrench in one direction and subsequently recoils back with a velocity in the opposite direction.

Let v and V be the velocity of the wrench and the velocity of the astronaut respectively.

In space, there is no external force acting, the momentum must be conserved.

So, m(0)+M(0)=m(v)+M(V)

So, 0=mv+MV

$\Rightarrow mv=-MV$ ...(i)

Here, the momentum of the wrench = mv, and the momentum of the astronaut= MV. The negative sign showing that both the momentum are in opposite direction.

Therefore, the momentum of the wrench is equal and opposite to the momentum of the astronaut.

According to Newton's second law, the rate of change of momentum = applied force.

Let it take $\Delta t$ seconds to change the momentum.

So, for the wrench

$m(v-0)/\Delta t= F_w \\\\\Rightarrow m(v-0)=F_w\Delta t \\\\\Rightarrow mv=F_w\Delta t \cdots(ii)$

Here, $F_w\Delta t$ is the impulse applied to the wrench.

Similarly, for the astronaut

$M(-V-0)/\Delta t= F_a$ [negative sign (-V) for opposite direction]

$\Rightarrow M(-V-0)=F_a\Delta t \\\\\Rightarrow -MV=F_a\Delta t$

Here, $F_a\Delta t$ is the impulse applied to the astronaut.

So, the impulse on the astronaut.

By using equations (i) and (ii)

$F_a\Delta t=F_w\Delta t$

Therefore, the impulse applied to the wrench is equal and opposite to the impulse applied to the astronaut.

Hence, option (a) is correct.

3 0

3 years ago

A wave travels with a speed of 78m/s in air and it has a frequency of 42hz.What is the wavelength of this wave?

stiks02 [169]

Answer:

1.9 m

Explanation:

78 m/s / (42 cycles/s) = 1.8571... m/cycle

5 0

3 years ago

Roger runs a marathon. His friend Jeff rides behind him on a bicycle and clocks his speed every 15 minutes. Roger starts out str

Fudgin [204]

Answer:Lower estimate 5,5 miles Upper estimate 6,25

Explanation:

First let's consider that 15 minutes is equal to 15/60 hours, that is 1/4=0,25 hours, we need this since the speed is given in miles per hour, then the time should be in hours too.

For the upper estimate, we assume the speed is constant on the highest possible value, that is the one at the start of the interval, for example from 0 to 15, there are two possible speeds 13 or 12 mph, for the upper estimate we consider the 13 and for the lower we consider the 12 a follows.

Upper estimate:

Speed_0-15= 13 mph then the distance_0-15=13 mph*1/4 hours=3,25 miles

Speed_15-30=12 mph then the distance_15-30=12 mph*1/4 hours=3 miles

Then Distance_upper-estimate= 3,25 + 3 = 6,25 miles

Lower estimate:

Speed_0-15= 12 mph then the distance_0-15=12 mph*1/4 hours=3 miles

Speed_15-30=10 mph then the distance_15-30=10 mph*1/4 hours=2,5 miles

Then Distance_upper-estimate= 3 + 2,5 = 5,5 miles

All this because we consider the distance traveled X at constant speed is given by X=v*t, v:=speed, t:=time

7 0

3 years ago